Lubricant cooling arrangement for outboard propulsion apparatus



APril 30, 1968 HIROSHI TADO ETAL 3,380,443

LUBRICANT COOLING ARRANGEMENT FOR OUTBOARD PROPULSION APPARATUS Filed Dec. 2, 1964 2 Sheets-Sheet 1 FIG.

ATTORNEYS April 30, 1968 HIROSHI TADC) ETAL 3,380,443

LUBRICANT COOLING ARRANGEMENT FC'R OUTBOARD PROPULSION APPARATUS Filed Dec. 2, 1964 2 Sheets$heet '7 ATTORNEYQ;

United States Patent 0 3,380,443 LUBRICANT COOLING ARRANGEMENT FOR OUTBOARD PROPULSION APPARATUS Hiroshi Tado, Suita-shi, and Mitsuhiro Ota, Nagahamasill, Japan, assignors to Yanmar Diesel Engine Co., Ltd., Osaka, Japan, a corporation of Japan Filed Dec. 2, 1964, Ser. No. 415,350 Claims priority, application Japan, Dec. 6, 1963, 38/9l,172 2 Claims. (Cl. 123-196) ABSTRACT OF THE DISCLOSURE An outboard propulsion apparatus having an internal combustion engine driving an output member and a closed housing disposed between the engine and the output member. A vertically extending partition separates the housing into two sections, one of which is formed into an oil sump, and the other of which has an oil cooler core disposed therein. The exterior surfaces of the core and the interior surfaces of the latter section together define a water jacket section through which cooling water is circulated so that it simultaneously cools oil passing through the core and in the sump.

The present invention relates to outboard propulsion apparatus of the type having an engine which requires the provision of a lubricating oil sump and a lubricating oil cooler.

It is widey acknowledged that simplification of cooling and lubricating oil systems for the engine in outboard propulsion apparatus of the type described above offers many advantages which include reduction in the volume and weight of the apparatus with attendant reduction in the cost and simplified structure and procedure for operation.

The primary object of the present invention is to pro vide an outboard propulsion apparatus of the type described which is provided with a lubricating oil sump and a lubricating oil cooler of simplified structure.

In order to attain the above-described object, the present invention proposes an outboard propulsion apparatus of the kind described which comprises means for providing a lubricating oil sump and a lubricating oil cooler in side-by-side relation to each other in an intermediate body portion of said apparatus in a manner such that the water jacket section of the lubricating oil cooler is disposed adjacent the lubricating oil sump, a partition separating the lubricating oil sump from the lubricating oil cooler is provided, and means for circulating cooling water through the water jacket section of the lubricating oi cooler is provided so that the cooling water flowing through the water jacket section of the cooler can simultaneously cool the lubricating oil in the cooler core of the oil cooler and the lubricating oil in the lubricating oil sump. It is therefore possible, according to the present invention, to sufficiently attain the purpose of cooling the oil even with a lubricating oil cooler of small capacity and the present invention is quite advantageous for the simp'ification of the structure and for the reduction of the volume of the outboard propoulsion apparatus. Further advantages derivable from the built-in structure of both of the lubricating oil sump and the lubricating oil cooler in the intermediate bodyportion of the outboard propulsion apparatus of the invention are that the equipment of the engine part of the ship can thereby be simplified and that the lowered center of gravity provides added stability when installed on the ship.

Other objects and particularities of the present invention will become obvious from the following description with reference to the accompanying drawings, in which:

3,380,443 Patented Apr. 30, 1968 FIG. 1 is a side elevational view, with parts in vertical section, of the outboard propulsion apparatus embodying the present invention, in which the engine is not shown because it is not directly related with the invention;

FIG. 2 is a sectional view taken on the line A-A in FIG. 1; and

FIG. 3 is a sectional view taken on the line BB in FIG. 2.

Referring to the drawings, the outboard propulsion apparatus according to the present invention includes a luricating oil sump 1 and a lubricating oil cooler which are disposed adjacent to each other in an intermediate body portion between the engine mounting portion and the propeller mounting portion of the apparatus, and are separated from each other by a partition 29 interposed therebetween. The oil cooler includes therein a water jacket section 5 which surrounds a cooler core 3. In the invention, the water jacket section 5 of the oil cooler is disposed on the side of the oil sump 1 for the reason as will be described later. A propeller driving shaft 27 extends verticaLy through the propulsion apparatus, and a cooling water pump 11 and a lubricating oil pump 7 are coaxially mounted for operation on the driving shaft 27, as shown in FIG. 1. Cooling water is drawn by the cooling water pump 11 through a strainer screen 25 in a cooling water intake port provided rearwardly of the propeller and through a cooling water conduit 13 connected to the discharge port of the pump 11 into the water jacket section 5 of the lubricating oil cooler to cool lubricating oil passing through the core 3 of the oil cooler. The cooling water also acts to cool a portion of lubricating oil in the lubricating oil sump 1 through heat exchange through the partition 29. A plurality of vertically extending cooling fins 19 protrude inwardly from the partition 29 into the J oil sump 1 as shown in FIG. 3 to enhance the cooling effect by the cooling water. From the oil cooler, the cooling water is fed upwardly into the engine (not shown) to cool the same and the greater portion thereof is discharged outwardly of the apparatus from a water discharge port 21 at a rear portion of the apparatus, while the remaining small portion of cooling water is discharged together with engine exhaust from an exhaust port 23 at a lower portion of the apparatus.

Lubricating oil is filtered clean by an oil filter 9 provided on the bottom of the oil sump 1 and is drawn by the lubricating oil pump 7 disposed below the oil sump 1. In FIG. 2, the lubricating oil discharged from the lubricatin oil pump 7 is fed through an oil conduit 15 into the oil cooler core 3 for being sufficiently cooled therein, thence through an oil conduit 17 into the engine. After having lubricated and cooled the engine, the lubricating oil drains downwardly from a lower portion of the engine and flows through an oil discharge port 31 above the oil sump 1 to return to the oil sump 1 while impinging against the partition 29 at an acute angle therewith. This manner of oil return into the oil sump 1 provides an increased rate of heat transfer between the lubricating oil and the partition 29 with the integral cooling fins 19 and at the same time provides a greater contact temperature difference between the lubricating oil and cooling water, or the temperature difference between them due to the fact that they are flowing in opposite directions and are in a state of turbulent flow, the overall effect being a better heat flow between them. This provides an increased amount of heat radiation and an improved cooling effect. According to the usual practice, an oil filling port 33, an oil inspection rod 35 and a drain plug 37 are provided on the oil sump 1.

What is claimed is:

1. An outboard propu'sion apparatus having an internal combustion engine driving an output member located below said engine, wherein the improvement comprises 3: a closed housing disposed between said engine and said output member, a vertically extending partition separating said housing into two sections, a plurality of cooling fins extending from said partition into one of said sections, an oil sump formed in said one section, an oil cooler core disposed in the other of said sections, the exterior surfaces of said core and the interior surfaces of said other section together defining a water jacket section, means to pass oil upwardly through said core into said engine, oil return means to direct the flow of oil downwardly from said engine over said fins and into said sump, said oii return means being arranged so that said oil impinges against said partition at an acute angle, and means to circulate cooling water upwardly through said water jacket section so that it simultaneously cools the oil in said core and in said sump.

2. The apparatus of claim 1, further comprising a plurality of cooling fins extending outwardly from said core.

References Cited UNITED STATES PATENTS 1,536,499 5/1925 Horvath 12341.33 X 1,761,686 6/1930 Schloerb 184-104 2,054,403 9/1936 Yeager 184-104 X 1,763,970 6/1930 Johnson.

FOREIGN PATENTS 6l9,739 4/1961 Italy.

LAVERNE D. GEIGER, Primary Examiner.

E. EARLS, Assistant Examiner. 

